How much and how often to water avocado trees in California

I’ve always wished there were a simple formula that could tell us how much and how often to water an avocado tree. Alas, the variables are too numerous and complex: weather is ever-changing, different soils have different capacities, each method of watering creates distinct conditions, etc.

Yet I bulled forward and made this table anyway, showing approximately how much and how often to water avocado trees of different sizes in each month of the year in Southern California.

Table showing how much (in gallons per month) and how often to water avocado trees in California.

Even though such a table cannot be perfectly accurate, it’s pleasantly usable. Even if you follow the table blindly without making any adjustments, your tree is likely to do well.

If you are interested in being a little more efficient and effective, you can tailor the application of the numbers by keeping in mind a handful of things about how I made it and how avocado trees use water.

How did I come up with these numbers of gallons? I used weather information that is similar to where most people in Southern California live — basically, the valleys: roughly five to fifteen miles away from the beach. (Specifically, it’s Zone 6 on this map.) Anaheim in Orange County is an example of a city in this zone. If you live closer to the ocean, well, aren’t you cool and comfortable? And so is your avocado tree. You can give it 10% less water in the summer. Likewise, if you’re more than fifteen miles from the ocean, your avocado tree feels the heat and might enjoy 10% more gallons than the table shows for the summer months.

But these numbers aren’t just theoretical. They are also based on the quantity of water that I have found to work well on my avocado trees.

In my experience, you can’t give avocado trees much less without them suffering. (I’ve tried.) And it’s unnecessary to give them much more. (You won’t get more fruit, which is the point.)

Frequencies are for sprinkling and mulch

The table makes a couple of assumptions. One is that you are sprinkling or spraying the water under the tree, not using drip emitters. If you are using drip emitters, then the gallons don’t change but the frequency does. You must water more often with drip, every two or three days in summer, for example.

Another assumption is that there is mulch under your avocado tree. Leaves or wood chips under an avocado tree are extremely beneficial in myriad ways, one of which is allowing the tree to go longer between waterings. If you don’t have mulch under your tree, you really ought to add some.

What did I base the table’s frequencies on? If you’re familiar with the concept of evapotranspiration (ET), then you might be interested in knowing that the table says to water after about one inch of ET has occurred. If you’re not familiar with ET, then forget that. Just know that the table’s frequencies are what I’ve found avocados to prefer.

If avocados are routinely watered too often, they become susceptible to root rot disease, among other problems. If avocados are watered too infrequently, they stress and their leaves brown and they might even drop fruit. My table’s frequencies are the safe and happy medium.

Also, be sure to increase the frequency during severe heat waves. When the extreme heat of July 6 and 7, 2018 hit Southern California, you needed to water every day. I saw the avocado trees in the area that didn’t get that custom care; they suffered. (Here is my strategy for watering when extreme heat hits: “How to water plants through a heat wave.”)

No automatic watering in winter

Where avocados grow wild, winters are even drier than ours in Southern California. So once our rains begin, sometimes in November but more reliably in December (December 2017 notwithstanding!), you should stop watering your avocado tree automatically. (That’s why the table shows the frequencies for those months in parentheses.)

Unnecessary irrigation in the winter not only wastes water but more importantly can keep the soil soggy and disease prone. After we’ve had our first couple inches of winter rain until around the end of March, only water an avocado tree if there is a dry spell of at least a couple weeks.

And when you do water, give the tree approximately the amount it has used in that interval according to the table. For example, for a 10-foot tree in February that has received no rain for two weeks, give it about 55 gallons. (That number comes from 110 gallons for the month divided by 28 days, times 14 days.)

Big trees get water elsewhere

The table only goes up to 14 feet mostly because bigger trees in a normal yard will have grown extensive root systems that drink from neighboring plants, maybe even from your neighbor’s plants. So if you have a big avocado tree, you almost surely can give it less water than an avocado farmer would have to give such a tree in an orchard.

It’s impossible to say how much to give your big tree. Just think about what is being watered under its canopy and even within ten feet or so of the outer edge of its canopy. If there are irrigated plants all over that area, then you might not need to give the tree any water of its own. This is particularly true if there is lawn being watered within the tree’s reach.

No one waters this old Bacon avocado tree directly, but it does fine drinking from the lawn’s watering.

Using the table: a small tree

Here’s an example of how I can use the table to water one of my trees. I have a Gwen avocado tree that has a canopy diameter of about three feet.

Gwen avocado tree with three-foot canopy diameter.

Here in June, the table says that such a tree needs to be given about one gallon per day. I get this number by dividing 28 gallons by 30 days. And I’m supposed to water it every five days. This would mean giving it about five gallons every five days.

I water this Gwen avocado tree with a micro-sprinkler. I measured how much water the micro-sprinkler puts out by turning it on, sticking it into a bucket, and timing it. I found that the water in the bucket filled to one gallon after ten minutes. That’s the equivalent of six gallons per hour. If I want to give the tree its five gallons, then I should run the sprinkler for just under an hour.

What I’ll do in reality is round up. I’ll water for an hour every five days in June. One reason for this is that the sprinkler is set to spray a little beyond where the tree’s roots are. (I know this because I’ve poked around down there.) So I’m potentially wasting some water, but it’s worth it because I want the tree to be able to expand its root system as rapidly as possible, giving it fortitude during temperatures over 90. This happens with some frequency in summer because my yard is twenty miles from the ocean. For this reason I also need to add about 10% to the gallons in the table.

Young trees like this Gwen can grow fast: beware. By September, its canopy might be four or even five feet wide, meaning it will need more water to fuel those extra leaves. It will have rapidly graduated out of the “3 feet” column.

Using the table: a big tree

One more example, this time with a bigger tree. I have a Hass avocado tree, and I measured its canopy to be 14.5 feet in average diameter. The summer of 2018 will be its sixth summer in the ground in my yard.

Hass avocado tree with 14-foot canopy diameter.

Here in June, the table says a 14-foot tree needs to be given about 20 gallons per day. I get this number by dividing 611 gallons by 30 days. And I’m supposed to water it every five days. This would mean giving it 100 gallons every five days.

I also water this Hass avocado tree with a micro-sprinkler, and I have measured that this sprinkler applies about 25 gallons per hour. So to give the tree 100 gallons, I must run the sprinkler for four hours. I’ll add a little extra to that because the tree’s already a tad over 14 feet and because of my hotter location.

35 Comments

I know some will hate that I’m going to say this, but…. you really should charge a fee for all this research and knowledge. For those with your constitution, I imagine they already constructed their own watering table, but for folks like me who are a tad too preoccupied and/or less disciplined, this watering table is a great help. I appreciate all your hard work, enjoyment, and sharing, Greg. I owe you one (or two). Jeff

Hi Greg – I have recently planted a GEM Avocado tree (3 mo ago). It’s about 6′ tall. It gets full sun and soil content is moderate clay but drains pretty good since I planted on a mound approx. 8″ higher than surrounding soil. It hasn’t flowered but had a good amount of new growth with some older leaves having some browning on the tips. It has stopped all new growth but majority of the leaves are green. I am worried about the abrupt stop in new growth. Can you give me any ideas? I’m in Aliso Viejo ca.

Most likely, your GEM is fine. Avocado trees grow in “flushes.” They usually have three or four each year here in Southern California. Starting from winter, they’ll flower and then have their first flush of new growth (red leaves at first). Then they pause. Sometime in summer they’ll have another flush of new leaves. Pause. In late summer or early fall, they’ll have another flush.

Each variety is on a slightly different schedule, but this is generally how avocados grow new leaves. So, probably, your GEM will flush again within the next month or two and right now it’s just in between flushes.

Hi Greg,
I have 2 trees, 2 problems.
In 2017 I planted a 15 gallon Reed in the ground north side of house in North Tustin. I also repotted a 5 gallon HAAS into a giant whiskey barrel kept in south west side of small backyard. Both had some fruit but only one Haas fruit fully matured. Both adapted very well and looked very healthy with lush leaves and vigorous growth. I was hoping for more fruit in 2018, but Reed had very few flowers (only has 2 fruit) and haas never flowered. What stunted the flowering? Can flowering be induced in healthy avocado trees? If so, how and when?
2. My beautiful haas suffered serious sunburn from 115 degree temps during 7/6/18 heatwave. He looked great that morning when I drenched his barrell, but by 5pm all 2″ new shoots were wilted and completely dried out, many leaves toasted brown and a few branches burned brown on top. The barrell was boiling hot to the touch. It was shocking how fast the sun damaged such a healthy looking tree! We built a cover to block the sun. I will paint his burned branches with white paint today (thanks for that tip!). Does he need special watering? Will misting him during this excessive heat help or hurt? He is over 12′ tall with 5′ canopy in the barrell. I would hate to lose him. Any advice would be great. Thanks

North Tustin is a great place to grow avocados. Two of my friends grew up there and I know the area pretty well. Your trees are going to do great in the long run. This heatwave, unfortunately, torched avocado trees from Ventura down through San Diego, including my own.

When the temperature reaches above around 105, young avocado leaves start melting and there’s almost nothing you can do about it. If possible, putting shade over a tree helps. I did that with some of my small trees. Also, yes, misting does help. The problem is that at such high temperatures, the water almost instantly evaporates. Therefore, in order for the misting to have a real cooling effect it has to be continuous. But if it is continuous, it can definitely cool and save avocado leaves.

During heat like we just experienced (I think the worst is over?!), a tree in a barrel is more vulnerable than a tree in the ground because the barrel’s sides heat up and roots on the sides can be damaged. Shading the barrel’s sides would help. It may also be necessary to water multiple times in a single day.

As for your Reed, it can only be expected to bear a real crop of a dozen or more avocados in its second or third, maybe fourth, year in the ground. So expect a fruitset like that in the spring of 2019. There are techniques to induce flowering, such as girdling, but sometimes they end up causing a tree to bear a lot of fruit that year and then having very little fruit the next year. Reed is a variety that is highly productive everywhere I’ve observed, but it just needs a couple years in the ground first.

As a typical example, I have a Reed planted as a five-gallon tree in 2013 that set its first fruit in 2015 of nine avocados, which we ate in the summer of 2016. So that’s three years in the ground until eating the first fruit. (But since your tree was a 15-gallon, you can expect to be a year ahead of that.) Then its next crop was 35 avocados which we ate in 2017.

By the way, this Friday’s post will be all about the terrible, record-setting Southern California heatwave we just went through and all of the lessons I can gather from it, including how to get your avocados through such an event. Thank you for getting me started on it!

Avocado questions
1) Hello. Very happy to find your blog. It’s great. I just bought two avocado trees for my backyard, one 15-gallon Hass and a 5-gallon Fuertes. Since planting them 2 weeks ago I have been going slowly insane. I did a test soil drainage test. If was 4.5 hours before the hole drained for the second time. Also, the PH around the tree is 5.35
2) The tag on the tree itself (the Fuerte) said to bury the bulb of the tree 2-3 inches below the surface to prevent the cold weather from getting to it. So we did that for both. And we put a well around it that goes down one foot, and it’s three feet across for the big one and 2.3 feet for the little one. Since then, I have been reading a lot and most sources say to do the opposite, as far as putting the bulb a few inches below the ground. What to do? Since I just planted them two weeks ago, I don’t want to dig them up again, I think that would kill them. My guess is just leave it alone. Right?
3) The nursery gave us a starter kit, and it has a starter fertilizer with it. I got someone to follow all the directions and put it in as instructed while I was at work. But the starter fertilizer is only 2% nitrogen, and most authorities seem to say nitrogen is the main thing they will need. So I ordered some ammonium sulfate and plan to add it now. Am I right, or should I wait?
4) We hit a high of 113, and the next morning the bigger one, the Hass, suddenly had all the leaves noticeably wilted. The day before they were pointing up, looking good, the next morning they were all pointing down, 100%. I figure it was the heat and the tree needed to be shaded, so I ordered shade cloth and plan to drape it over the tree until the high temperature for the day gets down to 90 or below. Right?

2) Where do you live? Can you tell us which store or grower printed that information on the tag? That’s horrible advice. I know it sounds very unappealing, but now that the weather has cooled (relatively speaking) I’d dig them up and replant. You can do this successfully especially if you do it in the evening, water the trees lavishly right after replanting, add lots of mulch, and shade them for a couple weeks. See my post, “How to plant and stake an avocado tree”: http://gregalder.com/yardposts/how-to-plant-and-stake-an-avocado-tree/

The reason I wouldn’t just leave the trees as they are is that they often settle even lower over time, your drainage is okay but not exactly fast, and if we get lots of rain this winter your trees might rot.

Alternatively, you can leave them be and water them very carefully. This summer you’ll have to water near the trunk because that’s where the roots are now. But starting in the fall, water only a foot or more away from the trunk to make sure water doesn’t keep the trunk moist.

3) I wouldn’t fertilize now. Mulch 3-6 inches with wood chips or leaves and possibly add a little compost. Mulch and compost safely offer nutrients to soil microbes which then offer it to the trees whereas it is easy to overdo chemical fertilizers and burn a young tree.

4) You’re perfectly right about the heat and the shade. Do exactly as you said.

Hi, I have Haas Avos and live in San Bernardino area ( with lots of afternoon wind). Why would I not want to water twice daily instead of every 5 days? I have decomposed granite soil and find that it will run off if I water for long periods of time?

There are many small factors that go into finding a good watering frequency for your avocado trees, and one of them is definitely wind. I can’t say for sure that watering twice daily is not good for your trees. But do know that for about a hundred years avocados have been grown commercially in similar situations (Riverside, Hemet, even parts of Spain and Israel) and they have never seen the need to water twice daily as a normal summer routine, unless the irrigation method is drip and not sprinkler.

The best way to prevent runoff is to add a thick layer of coarse wood chip mulch under the tree. If you still get runoff with that mulch, you can try giving the tree a very light watering initially to make the soil ready to absorb water, then come back after maybe 15 minutes and apply the bulk of the water.

If that doesn’t work for your situation, let me know and I’ll suggest other strategies.

I have a 50 year old avocado tree in my backyard. We just bought this property a few months ago. The avocado tree had over 200 fruit on it, but the heatwave we recently had destroyed the entire tree. All of the leaves fell off, small branches fell off, and all of the fruit of course fall off. I’ve been doing my best to water it to keep it hydrated, but how much water should I be giving this tree and how often during these months of intense heat?

Also, if I were to build a large shade around this tree, what do you recommend? Like a mesh overhang so some light can penetrate?

And my last question, which is the more serious concern of mine. I think the tree may have termites as I’m seeing a lot of droppings that look like coffee grinds. I haven’t dug up around the tree yet to confirm, but in the event it does have termites, what is the best way to save this tree from them???

I’ve never personally dealt with an avocado tree infested with termites, but I know that professional pest control operators do this kind of work.

However, if the tree has actually lost ALL of its leaves, then it’s possible that dealing with the termites now is futile. Paint all of the exposed limbs, and then water cautiously. Even though it’s tempting to try to help the tree by giving it a lot of water, a tree that has no leaves needs very little water. So you run the risk of rotting its roots. Feel the soil where the roots are in order to see when it has dried out somewhat, and only give the tree water then.

Thank you for posting your chart on how much to water an avocado tree in Southern California. You tell how many gallons of water to use and how often, but I do not know how to guage how many gallons we are using. How do we measure the gallons per hour? We use micro spray emitters. Also your chart goes up to a tree 5 years of age. Should I assume that after 5 years it is the same for older trees?
Thank you,
Louise Roberts

I mentioned in the post above how I measure the output of my micro-sprinklers. Maybe you can use this method? “I measured how much water the micro-sprinkler puts out by turning it on, sticking it into a bucket, and timing it. I found that the water in the bucket filled to one gallon after ten minutes. That’s the equivalent of six gallons per hour. If I want to give the tree its five gallons, then I should run the sprinkler for just under an hour.”

The reality is that it doesn’t matter how old a tree is, it matters how big (how many leaves) a tree has. But I gave the ages of trees that are typically that size just for quick, rough reference.

I only went up to 14 feet (or about 5 years old) because trees bigger than that in a typical yard are drinking water from nearby plants and it’s not very useful to know how much water they would need if they were planted alone, far from any other irrigated plant. So, if you have a typical yard and an avocado tree larger than 14 feet, it’s better to water them based on feeling the soil under their canopy and observing their foliage.

If you have a very large yard with a lone, large avocado tree, let me know and I’ll give you a formula for figuring out approximately how many gallons it will use.

I have all of my avocado trees in large pots. I also have 1/4 inch plywood cut to match the top of my pots on the south and east sides, painted white. I got hurt by the hot spell but not the same on each tree. My year old Sharwil and two year Wurtz were hardly damaged, just a few leaves on the south side. I also paint all of my trees exposed limbs with 1/2 latex white paint and 1/2 water. My year old Reed was hit the hardest and is iffy as there are only two places where there is new growth. My Sir Prize has a fairly large spourt of new growth that I think will eventually be the tree its self as almost all the rest is brown. My Holiday is showing growth in several areas on the tree and I think it will also recover. I have a frost type cover over all the trees right now, in fact I added a Lamb Hass and a Carmen Hass, each about two to three feet tall. I added a Dwarf Hardy Cold avocado today, all three are covered under the cover and the new one I will paint its limbs tomorrow. I have a couple of questions as to proceed. First, I can order another Reed and remove the injured one now or wait till perhaps in November. This would give me some time to see if the Reed will recover. Ignoring the cost, would a new Reed have better growth and thus fruit sooner than nursing the damaged one?
Second, I use a earth probe that shows whether the soil about 10″ deep is moist or dry. I check each tree and if it shows on the high moist, I will skip a day before checking it again. I haven’t had any that went from high moist to dry in even two days, thus far.
I also use a foliage spray (Organic Plant Magic) which is also poured on the soil. It is a type of compost tea and I have seen really great growth on almost all my plants. I did give the new growth a light spraying, do you think I should only use it a week apart spraying? I am located in Eastvale which is west of Riverside. The Santa Ana River is about 100 yards east of my home. I have been delighted by your site and posts. You are a real jewel!

You’ve got a fantastic collection of avocado varieties there. I would guess that a new Reed would outgrow your damaged Reed based on how slow it has been to bounce back compared to the other trees.

I don’t know anything about Organic Plant Magic and their website doesn’t say what is actually in the product. What I do know is that researchers haven’t found avocados to be particularly receptive to foliar feeding. See this recent article: http://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=27840

Nevertheless, if you’re satisfied with how your trees are doing, then maybe you should keep doing it. If it ain’t broke . . .

As you know well, avocados in pots are different beasts compared to avocados in the ground.

I’m so happy to have found these posts. Thank you for being so helpful!

We are up in Eagle Rock, CA and have three giant Fuerte avocado trees about 25 feet high and canopies about 30 feet across(1 of them may be a Pinkerton though). The trees have been producing like gang busters for several years and we have done precious little to help them along. After these several years of drought, I’m seeing a few smaller branches toward the outside of the canopy dying off while most of the interior branches appear to have healthy green leaves. One of the trees seems to have many gaps in the canopy and I am concerned about the interior getting scorched. They had a nice burst of production a few weeks ago but so many of those little green balls have since fallen off.

We have not specifically watered the trees a whole lot. One of them probably gets most of its water from the yard area which has sprinklers. They run for 15 minutes each section. The other two trees lie right between our house and the driveway but the canopies extend to and over the neighbors yard so assume that’s where they are getting their water.

I’m wondering what I can do to halt the dying of the branches and or encourage their health. I have no mulch underneath any of them but was planning on doing that ASAP. I’m not sure how to water 2 of the trees do to their proximity to so much concrete but it is the third one I am most concerned about with the gaps in its canopy.

Any and all watering and feeding suggestions would be appreciated.
Thanks so much!
Mike

Sounds like you may be looking at a root rot situation with the one tree. Coarse mulch will certainly help with that or even if the tree is healthy. Good idea to add mulch wherever you can.

It may also help to occasionally water a lot, just one time. This pushes salts down below the trees’ roots. Some people find success doing it once per month during the summer. It’s tough to say how much to water, exactly, but often just running your normal irrigation cycle for twice as long will do the trick.

Adding gypsum is said to help with root rot, but only as part of an overall scheme which includes good irrigation, mulch, etc. You might want to get a better idea of whether or not root rot is your issue first. A simple start is to scratch under the tree and find roots: if they’re white or cream colored when broken, that’s good; if they’re black, mushy, rotten smelling, that’s bad, that’s probably an infection.

Hi Greg. You mention different watering frequencies/quantities for drip vs. micro-sprinklers. Would you recommend one over the other? I am currently using soaker hoses buried under layer of mulch for two 8-10ft trees (Sir Prize and Lamb Hass). I am constantly questioning my methods, and wonder if watering on top of mulch would replicated what happens in nature the best. I live in Pasadena and the soil here drains instantly. A two foot hole won’t hold water for more than 10 mins. Thanks!

Your climate and soil seem very similar to mine. I know Pasadena; I grew up in the San Gabriel Valley. And my soil drains out of a hole in about ten minutes too. Both factors together mean that micro-sprinklers are likely to work slightly better than drip for us.

(I’ve been thinking of writing a whole post about sprinkler vs. drip for avocados. Maybe I’ll do it this winter.)

I’ve used both on avocado trees here in Ramona (twenty miles from the ocean in San Diego County) and found slightly better results from micro-sprinklers. Most commercial avocado growers in California use micro-sprinklers now after trying to use drip for decades starting in the 1970s.

What happens is that young trees do fine on drip, but bigger trees start to struggle in our summer heat. Your trees might do fine on soaker hoses though. Soaker hoses apply water more broadly than drip emitters, especially if the hose is spiraled under the canopy.

Watering under the mulch has the advantages of less evaporation and being more attractive, but laying the hoses over the mulch wets it and causes it to break down faster, meaning it is adding organic matter to the soil faster and also meaning the tree’s roots can poke up into the mulch more and get air and nutrients.

When I used soaker hoses, I hated tripping over it when it was above the mulch though. A compromise that you can follow is keeping the soaker hoses under the mulch, but then soaking the mulch with a hose or sprinkler every month or so in the summer.

Hi Greg!
I live in Camarillo and have 4 mature HAAS trees. I have them on micro sprinklers and get a nice circular soak between all trees. I have noticed a lot of “chloride burn” on the leaves and fruit this year. Per your advice, I flushed the soil (24 hrs on the sprinklers) about a week ago. Is it too late in the year to try for another flush to get out some of that built up chloride?
Thanks! Love your info!

Thanks for writing. It’s not too late! This time of year (mid-fall), salt concentrations are often highest because we still haven’t received significant rain. Leach as necessary.

This has been a tough irrigation year since we got almost no rain last winter and then the summer was extra hot. My Hass is now showing tip burn too, which I expect will worsen until new growth in late winter.

I’d like to plant my first two avocado trees. I like Haas from the store, is there a specific Haas type you recommend?. Do you recommend a particular nursery to mail order from? I’m located in the far southern tip of Texas, should be a good growing location. Thank you!

If you like Hass from the store, then you’ll go crazy for Hass off your own tree. Hass trees are widely available and hard to beat even though some Hass sports like Carmen and Maluma are interesting. Hass relatives like GEM and Lamb are good varieties too. I can’t imagine you’d be disappointed with any of them.

I’d recommend getting a Hass as one of your two trees, and then getting a second tree that complements Hass in some way. Either you can get a B type so there is cross pollination for extra fruit set (Bacon or Fuerte, for example) or you can get a variety whose harvest season is different (Lamb or Reed, for example). Actually, Bacon and Fuerte accomplish both goals since they are ready to harvest before Hass.

I don’t know what will work best in your part of Texas though. I’d try to find someone near you growing Hass to see if it does well. I may know such a person close to you if you can’t find anyone else. Let me know.

I’ve never mail ordered an avocado tree, but I have found Four Winds Growers in Northern California to be reliable with citrus, and they also ship avocado trees. I’d try them.

Can you tell the difference between overwatered vs underwatered avocado? From all the reading I did and talking to people, the symptom is the same. The leave turn yellow and wilted. Can you shed some information on this?

It’s true that just looking at leaves won’t give you an easy, clear answer about whether the tree is being underwatered or overwatered. But there are subtle differences to the look of the leaves in each situation.

When an avocado tree is being overwatered, the leaves not only wilt somewhat but also take on a pale yellow look whereas if a tree is being underwatered the leaves will not be that pale yellow color. Eventually, in the case of underwatering, the leaves start to brown at the margins.

But there are better ways to tell if a tree is being watered too much or if it’s thirsty. Feel the soil where the roots are. That’s the best test, always.

The second best would be to give it water and watch what response the leaves make. If the leaves perk up, then it was just thirsty. If not, then it wasn’t.